Constriction-sizing attachment for glass-tube constricting machines



1941., F. c. @HAEBE 2,230,075

CONSTRUCTION-SIZING ATTACHMENT FOR GLASS-TUBE CONSTRICTING MACHINES Filed Feb. 4. 1939 2 Sheets-Sheet l INVENTUR BY MM ATTO RN EY Jan. 28, 1941.- E Q CHASE 2230,4075

CONSTRUCTION-SIZING ATTACHMENT FOR GLASS-TUBE CONSTRICTING MACHINES Filed Feb. 4, 1939 '2 Sheets-Sheet 2 w lm wg; d1 WW WVENTOR' BY y ATTORNEY Patented Jan. 28, 1941 PATENT OFFICE CONSTRICTION-SIZING ATTACHMENT FOR GLASS-TUBE CONSTRICTING MACHINES Frank C. Chase, Brooklyn, N. Y., assignor to E. R. Squibb & Sons, New York, N. Y., a corporation of New York Application February 4, 1939, Serial No. 254,630

4 Claims.

This invention relates to the formation of constrictions in tubular glass articles (hereinafter termed glass tubes).

The production or processing of many glass 5 articles involves the formation of uniform constrictions therein. For example, pharmaceuticals are commonly packaged and sealed in glass ampules by introducing the pharmaceutical into the bulbuous body of an ampule (having a cylindrical stem), constricting a zone of the stem, drawing the constriction to a capillary, and, finally, sealing off the capillary while evacuating the ampule. Such operations are generally carried out with automatic machinery in which the ampules are intermittently passed to a constricting station whereat the ampules are rotated and the zone of the desired constriction on the stem is heated; the ampule is then passed to a drawing station where the constriction formed is drawn to a capillary; and the ampule is then evacuated and the capillary sealed off by means of a flame. Heretofore, difficulties have been encountered in such operations, owing primarily to variations in thickness of the ampule stem wall, causing, in turn, variations in the internal diameter of the constriction and resulting in the drawing of nonuniform capillaries therefrom. Thus, in ampuling pharmaceuticals there has been considerable spoilage due to underand over-sized capillaries, the latter permitting retraction of glass into the ampule when evacuating and sealing off, and the former, when of less than a certain diameter, being incapable of proper automatic evacuation. Besides, of course, many ampules have been completely sealed off at the capillary-drawing stage and hence have had to be discarded or subjected to the expensive procedure of reclaiming the contents.

It has been attempted to assure uniform capillaries by providing a, constriction-sizing (i. e., constriction-size-determining) attachment at the final constriction station prior to the drawing station. For this purpose a metal (e. g., tungsten) needle was lowered into an ampule (at the constricting station) to a position therein adjacent the desired constriction and cocentric to the axis of the ampule (the ampule being rotated and the constriction zone heated, meanwhile); the needle was then axially oscillated to prevent fusing of the constricted portion of the glass thereto and to gauge positively the size of the constriction. However, this attachment was not successful, because the needle became overheated by exposure to the hot glass, and particularly because in the operation of ampule-constricting machines,--as in most machines of this type-an operator often failed to load the ampule carrier, so that the needle was directly heated when lowered into constriction-sizing position and consequently 5 fused to or otherwise damaged the following ampule.

It is the object of this invention to provide an improved constriction-sizing attachment for glasstube-especially ampule-constricting machines, which is fully effective regardless of irregular feeding of the glass tubes to the constricting station.

Essentially the improved constriction-sizing attachment of this invention comprises a needle, means for intermittently lowering the needle into, and retracting it from, constriction-sizing position in a glass tube being constricted, and means for cooling the retracted needle.

The invention will be described in connection 20 with the accompanying drawings-showing an embodiment of the invention adapted for an ampule-constricting machine--wherein:

Fig. 1 is a fragmentary elevation of the constriction-sizing attachment and its operating mechanism;

Fig. 2 is a fragmentary axial section through the jacket shown in Fig. 1, with the constriction-sizing needle in fully-retracted position; and

Fig. 3 is a schematic representation of the position of the constriction-sizing operation with reference to the other operations in packaging and sealing ampules.

As shown in Fig. 1, the constriction-sizing attachment comprises a needle 23 carried by an 35 enlarged shank 2|, the shank being slidable within a jacket 22 supported above the constricting station of a conventional ampule-constricting machine (not shown) comprising means for holding the ampule and for rotating it while a flame 40 is directed to the zone of the desired constriction.

The needle is operated by means of a cross-bar 23 and connecting rod 24 (set screws being provided for appropriate adjustment). The connecting rod is slidable in standard 25, extends through 45 the base 26 of the ampule-constricting machine, and is actuated by a lever 40 journalled to said base. Lever 4|], through cam-follower 4|, is actuated by a rotating circular cam 42, the cam surface of which, 43, is adapted to vertically reciprocate connecting rod 24 (and consequently lower and retract needle 20) and to oscillate the needle axially when in lowered, constriction-sizing, position. Cam 42 is, of course, synchronized with the mechanism for intermittently feeding an ampule to the constricting station, as obvious to one skilled in the art.

Jacket 22 is provided with a gas inlet 38 adapted to receive a flexible hose 3i leading from a source of cooling gas, e. g. compressed air; and directly opposite said inlet is an upwardly curving gas outlet '32.

On retraction of the needle, the enlarged shank thereof passes gas-inlet 33, as shown in Fig. 2, and a cooling gas passes into the jacket and provides a cooling environment for the needle, and then passes out largely through the eXit 32. Thus the needle shank 2!, in cooperation with jacket 22, acts as a valve for the cooling gas.

The packaging and sealing of an ampule is schematically shown in Fig. 3, wherein 5i? represents a cam which actuates the drawing operations. At station I a filled ampule is placed in an ampule carrier and then intermittently subjected to a series of heating operations at stations here designated as II and IIIWhich may, of course, be more than two. At each of these stations (as well as station IV) the ampule stem is zonally heated while being rotated, and between these stations the ampule stem is held and the ampule bulb dropped slightly following cam 5?! to effect a slight drawing. Stage IV of Fig. 3 is the final constricting stage, where a, definitesized constriction is formed prior to drawing the capillary and where the constriction-sizing attachment of this invention is located. The drawing of the capillary is effected between IV and V as illustrated in Fig. 3 by the rapid descent there of cam 59; while the ampule stem is held, the ampule body is dropped precipitately, drawing a capillary from the sized constriction. VI represents the removal of the capillary-containing ampule, preferably after cooling as by means of an air-jet, and transfer thereof to a sealingcfi machine represented by VII. On this machine the ampule stem is connected to an evacuating hose 56, and while the tube is being evacuated the capillary Si is sealed ofi by a flame.

As indicated by the dotted lines in the schematic representation of constricting station IV in Fig. 3, the needle is oscillated while sizing the constriction, to prevent its fusing to the glass. The needle, as clearly shown, is situated eccentrically to the axis of the ampule, and serves to determine positively the minimum diameter of the constriction.

In the operation of a constricting machine embodying the constriction-sizing attachment of applicants invention, a missed loading of an ampule carrier will not aiTect the operation of the sizing attachment, since the intermittent cooling of the needle is sufficient to counteract the direct heating of the needle when no ampule is delivered to the final constricting station.

The cooling of the constriction-sizing needle is conveniently effected by compressed air; but the cooling environment may of course be either moist air or a mixture of air and atomized water (to take advantage of the latent heat of evaporation thereof), or any other suitable gaseous or vaporous medium.

The invention may be variously otherwise embodied within the scope of the appended claims.

I claim:

1. A constriction-sizing attachment for glasstube constricting machines, essentially comprising a needle, means for intermittently lowering the needle into and retracting it from, constriction-sizing position in a glass tube being constricted, a jacket surrounding and spaced from the retracted needle, and means for providing a cooling environment in the space between the jacket and the needle.

2. A constriction-sizing attachment for glasstube constricting machines, essentially comprising a needle having an enlarged shank, a jacket in which the enlarged shank is slidably mounted, means for intermittently lowering the needle into, constriction-sizing position in a glass tube being constricted, and retracting it from said position and into said jacket, and means for providing a cooling environment in the space between the jacket and the retracted needle.

3. A constriction-sizing attachment for glasstube constricting machines, essentially comprising a needle having an enlarged shank, a jacket in which the enlarged shank is slidably mounted, means for intermittently lowering the needle into constriction-sizing position in a glass tube being constricted, and retracting it from said position and into said jacket, and a passageway into the jacket for admitting a cooling gas into the space between the jacket and the retracted needle.

4. A constriction-sizing attachment for glasstube constricting machines, essentially comprising a needle having an enlarged shank, a jacket in which the enlarged shank is slidably mounted, means for intermittently lowering the needle into constriction-sizing position in a glass tube being constricted and retracting it from this position and into the jacket, and a passageway into the jacket for admitting a cooling gas into the space between the jacket and the retracted needle, the passageway cooperating with the enlarged shank of the needle to act as a valve for the cooling gas.

F. C. CHASE. 

